THE PERFORMANCE OF AN ANALYTICAL METHOD FOR DETERMINATION OF TBT DURING A 6-YEAR MONITORING PROGRAM

Tributyltin (TBT) concentrations have been measured in UK waters, shel lfish and sediments during the period 1986-1992. The methodology was b ased on conversion of alkyltin compounds to hydrides following extract ion, and then measurement by gas chromatography with flame photometric detection. The collection of a large set of data to assess changes in environmental concentrations of organotins required use of good analy tical quality control procedures at a time when no reference materials were available. An analytical quality control (AQC) system based on i n-house quality control materials was devised and the performance of t he method independently assessed by periodic participation in intercal ibration exercises with other expert laboratories.